Cover for manholes



y 1927- v w. J. WOODROW COVER FOR MANHOLES Filed 001;. 29 1926 My W A fill Patented May 31, 1927 v UNITED STATES PATENT OFFICE;

COVER FOR MANHOLESt Application filed October 29, 1926, Serial No. 144,980, and in Great Britain December 19, 1925.

The invention relates to covers for man holes and has for itsobject to provide im proved means for preventing the cover roclcing upon its seating in the trams. In this specification the term manhole is intended to cover not only a chainiiier such as the entrance to a sewer into which a manmay enter but also a smaller chamber such as is employed lfor making electrical connections, and a chamber into which drain pipes are led, and any chamber which is usually closed by an upper removable cover.

According to the present invention the cover is made or": separate triangular sections which are loose with respect to each other and the frame is provided with scatings to support each of the triangular sections separately at each angle. The separate triangular sections are preferably but not necessarily connected loosely together, as by bolts and nuts merely to prevent any one of the sections falling down through the hole in the frame should it he accidentally dropped. It will be understood that each triangular section seats itselt separately upon its three sea'tings and cannot rock thereon.

Two methods of carrying the invention into effect are illustrated in the accompany .ing drawings in which:

Figure 1 is a plan of a rectangular frame i with the square cover in position.

Figure 2 is a plan of the frame shown separately.

Figure 3 is a vertical section on the line 3---3 elf Figure 2.

Figure i is an underside view of the square cover shown in Figure 1.

Figure 5 is an elevation of one section of the cover seen from its longest side,

Figure 6 is a plan of a frame and part of a cover of hexagonal form.

The cover is made of a plurality of separate triangular sections a, a which are loose with respect to each other, each having on the upper surface projections Z), and having on its under face a downwardly projecting run a.

The triangular sections of the cover may,

if desired, be loosely connected together by any suitable means such as those shown in Figure l which consist of lock nuts 6 and bolts (Z passing through apertures f in the rim 0 which are olf larger diameter than the bolts (Z. The two sections of the cover shown in Figures 1 and 4, being loosely connected together, are free to seat themselves at their angles upon theseatings made to receive the same, and the completecover is larger in diameter than the hole in the frame.

The frame to receive the cover consists of a base 9 having the usual upstanding flange [L which has projections i on its upper surface and a central aperture Seatings 72, 7a to supportthe angles of the triangular sections of the cover are formed at all the inlerior angles of the flange h.

The cover shown in Figure 6 is hexagonal in plan and consists of six sections a, two 0t which are shown in position. The flange /& is likewise hexagonal to tit the complete cover. Seatings 7a are formed at all the interior angles of the flange it.

in this construction a bar Z forms part oi? the frame, passes across the aperture j and has a seating at its center to receive the central points of the triangular sections a. This bar Z is shown assupported at its ends in hearings on, thereby enabling it to be readily removed. These triangular sections may also be loosely connected together by any suitable means such as those shown in Figure 4. i

The construction herein shown and described prevents downward pressure being applied to any part of the triangular cover outside a line connecting two of its angles and consequently prevents the cover being rocked.

What I claim as my invention is 1. A cover for a manhole comprising in combination a plurality of separate triangular sections which are loose with respect to each other and which together form the cover proper, and a frame having seatings to support each of the said separate triangular sections at their three angles, substantiully as set forth.

2. A cover for a manhole comprising in combination a plurality of separate triangular sections which together form the cover proper, a frame having seatings to support each of the said separate triangular sections at their three angles, and means :for connecting the separate triangular sections loosely together substantially as set forth.

3. A cover for a manhole comprising in combination a plurality of separate triangular sections which together form the cover proper, a perforated rim on the under side of each separate triangular section, bolts loosely fitting the apertures in said rim, nuts for loosely securing said bolts, and a frame having seetinggal to snppore tliesehl separate trmgul'ar sections at their three angles substantially as set forth.

4. A cover for anmnhole eomprising in combination a plurality of separate triangular sections which are loose with respect to ot eluotheraml.w;l1ichtogether form the cover proper; a frame having straight sides anchseatinge loeaiecl atl alllthe*"'interior angles oi; the frame tosepanately support; the said separate tmnngnlar; sections snbstantmltv as:

set-.forthr l 5;,Al cover; for a manhole compels-1mg 1n combinablon a plurahty 0t separate trmngn- WALDER JOSEPHWOODRQW: 

